The use of radio communication systems through which to communicate is pervasive in modern society. Cellular communication systems, for instance, are deployed throughout significant portions of the populated areas of the world, providing users access to communicate therethrough when positioned in an area encompassed by a cellular communication system. Successive generations of cellular communication systems have been developed and deployed, each successive generation providing increased communication capabilities. For instance, while early-generation cellular communication systems were used primarily for voice communications, successor-generation cellular communication systems provide increased data communication capabilities. New-generation systems are capable of providing multimedia communication services at guaranteed levels of quality.
In a cellular communication system, and more generally, any radio, as well as another, communication system, channel bandwidth allocation is limited. The frequency spectrum allocated for use by a cellular communication system is limited, and such limitation is regularly a limiting factor in the communication capacity of the system. Effort is made, therefore, to utilize the allocated capacity in an efficient manner.
OFDM (Orthogonal Frequency Division Multiplexing) schemes, and other MCM (Multi-Carrier Modulation) schemes, e.g., provide the possibility of more efficient usage of channel bandwidth, thereby permitting increased speed for data to be communicated within a given channel bandwidth. In an OFDM communication scheme, sub-carriers are defined that are orthogonal. In an OFDM scheme, power management is an important function. Power efficiency, e.g., is, dependent upon power characteristics of communications upon OFDM-defined channels. One power characteristic of interest is a PAPR, Peak-To-Average Power Ratio. It is generally desired to communicate data at a relatively low PAPR. When the data leads to a higher PAPR, the power amplifier (PA) at a transmit station has to operate at a lower level of average power. When operated at the lower average power level, the resultant signal is of lower transmit power, and the coverage area of service is reduced. And, when operated at the lower average power level, the PA operates with a lower power efficiency, resulting in a higher service cost, and reduced battery longevity if the transmit station is powered by a battery power supply.
If a manner could be provided by which better to ensure that data that is to be communicated in an OFDM, or other MCM, communication system leads to an acceptably low PAPR level, communication improvements would be likely.
It is in light of this background information related to communications in an OFDM or MCM communication scheme that significant improvements of the present invention have evolved.